deleted optional packages from dockerfile

install optional packages by using env "PACKAGES" with value "package1 package2 package3"

Dockerfile

@@ -6,17 +6,12 @@ ENV DEBIAN_FRONTEND noninteractive
 
 # Install necessary packages
 RUN apt-get update && apt-get install -y \
-        android-tools-adb \
-        android-tools-fastboot \
         apt-utils \
         build-essential \
         curl \
-        ffmpeg \
         git \
         gnupg2 \
-        libfontconfig \
         libpam0g-dev \
-        libpcap-dev \
         libudev-dev \
         locales \
         procps \